Electrochemical lateral flow immunosensor with enhanced reproducibility for milk allergen detection

Electrochemical lateral flow platforms are applied for many applications due to their advantages of higher sensitivity in electrochemical detection than in conventional test strips. However, these devices have low reproducibility since the interface between the test strips and the electrode is difficult to replicate. Herein, for the first time, dual-working electrodes on a lateral flow immunoassay (dWE-LFIA) were used as an internal current on a single device, in which the current of both working electrodes was calculated as a normalized current to increase the device-to-device reproducibility. In this work, the detection of β-lactoglobulin, an allergen found in milk, was used as a model for evaluating the efficacy of dWE-LFIA. A study of reproducibility using this device showed a surprising 15-fold %RSD improvement compared to a single electrode on LFIA. Moreover, the analytical performance of this sensor for detecting β-lactoglobulin exhibited a wide linearity range of 1 to 1000 ng/mL and a detection resolution of 0.31 ng/mL. Therefore, our design of dWE-LFIA exhibited outstanding performance of high reproducibility, had high sensitivity detection, and could be applied and further developed for commercial biosensors in the future.